Module: Daru::IO
- Defined in:
- lib/daru/io/io.rb,
lib/daru/io/sql_data_source.rb
Defined Under Namespace
Classes: SqlDataSource
Class Method Summary collapse
- .dataframe_write_csv(dataframe, path, opts = {}) ⇒ Object
- .dataframe_write_excel(dataframe, path, _opts = {}) ⇒ Object
- .dataframe_write_sql(ds, dbh, table) ⇒ Object
-
.from_activerecord(relation, *fields) ⇒ Object
Load dataframe from AR::Relation.
-
.from_csv(path, opts = {}) ⇒ Object
Functions for loading/writing CSV files.
-
.from_excel(path, opts = {}) ⇒ Object
Functions for loading/writing Excel files.
-
.from_plaintext(filename, fields) ⇒ Object
Loading data from plain text files.
-
.from_sql(db, query) ⇒ Object
Execute a query and create a data frame from the result.
- .load(filename) ⇒ Object
-
.save(klass, filename) ⇒ Object
Loading and writing Marshalled DataFrame/Vector.
Class Method Details
.dataframe_write_csv(dataframe, path, opts = {}) ⇒ Object
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# File 'lib/daru/io/io.rb', line 103 def dataframe_write_csv dataframe, path, opts={} = { converters: :numeric }.merge(opts) writer = ::CSV.open(path, 'w', ) writer << dataframe.vectors.to_a unless [:headers] == false dataframe.each_row do |row| writer << if [:convert_comma] row.map { |v| v.to_s.tr('.', ',') } else row.to_a end end writer.close end |
.dataframe_write_excel(dataframe, path, _opts = {}) ⇒ Object
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# File 'lib/daru/io/io.rb', line 42 def dataframe_write_excel dataframe, path, _opts={} book = Spreadsheet::Workbook.new sheet = book.create_worksheet format = Spreadsheet::Format.new color: :blue, weight: :bold sheet.row(0).concat(dataframe.vectors.to_a.map(&:to_s)) # Unfreeze strings sheet.row(0).default_format = format i = 1 dataframe.each_row do |row| sheet.row(i).concat(row.to_a) i += 1 end book.write(path) end |
.dataframe_write_sql(ds, dbh, table) ⇒ Object
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# File 'lib/daru/io/io.rb', line 134 def dataframe_write_sql ds, dbh, table require 'dbi' query = "INSERT INTO #{table} ("+ds.vectors.to_a.join(',')+') VALUES ('+(['?']*ds.vectors.size).join(',')+')' sth = dbh.prepare(query) ds.each_row { |c| sth.execute(*c.to_a) } true end |
.from_activerecord(relation, *fields) ⇒ Object
Load dataframe from AR::Relation
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# File 'lib/daru/io/io.rb', line 147 def from_activerecord(relation, *fields) if fields.empty? records = relation.map do |record| record.attributes.symbolize_keys end return Daru::DataFrame.new(records) else fields = fields.map(&:to_sym) end vectors = Hash[*fields.map { |name| [ name, Daru::Vector.new([]).tap { |v| v.rename name } ] }.flatten] Daru::DataFrame.new(vectors, order: fields).tap do |df| relation.pluck(*fields).each do |record| df.add_row(Array(record)) end df.update end end |
.from_csv(path, opts = {}) ⇒ Object
Functions for loading/writing CSV files
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# File 'lib/daru/io/io.rb', line 59 def from_csv path, opts={} opts[:col_sep] ||= ',' opts[:converters] ||= :numeric = opts.keys.each_with_object({}) do |k, hash| if [:clone, :order, :index, :name].include?(k) hash[k] = opts[k] opts.delete k end end # Preprocess headers for detecting and correcting repetition in # case the :headers option is not specified. if opts[:headers] opts[:header_converters] ||= :symbol csv = ::CSV.read(path, 'rb',opts) yield csv if block_given? hsh = {} csv.by_col.each do |col_name, values| hsh[col_name] = values end else csv = ::CSV.open(path, 'rb', opts) yield csv if block_given? csv_as_arrays = csv.to_a headers = csv_as_arrays[0].recode_repeated.map csv_as_arrays.delete_at 0 csv_as_arrays = csv_as_arrays.transpose hsh = {} headers.each_with_index do |h, i| hsh[h] = csv_as_arrays[i] end # Order columns as given in CSV [:order] = headers.to_a end Daru::DataFrame.new(hsh,) end |
.from_excel(path, opts = {}) ⇒ Object
Functions for loading/writing Excel files.
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# File 'lib/daru/io/io.rb', line 22 def from_excel path, opts={} opts = { worksheet_id: 0 }.merge opts worksheet_id = opts[:worksheet_id] book = Spreadsheet.open path worksheet = book.worksheet worksheet_id headers = worksheet.row(0).recode_repeated.map(&:to_sym) df = Daru::DataFrame.new({}) headers.each_with_index do |h,i| col = worksheet.column(i).to_a col.delete_at 0 df[h] = col end df end |
.from_plaintext(filename, fields) ⇒ Object
Loading data from plain text files
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# File 'lib/daru/io/io.rb', line 174 def from_plaintext filename, fields ds = Daru::DataFrame.new({}, order: fields) fp = File.open(filename,'r') fp.each_line do |line| row = Daru::IOHelpers.process_row(line.strip.split(/\s+/),['']) next if row == ["\x1A"] ds.add_row(row) end ds.update fields.each { |f| ds[f].rename f } ds end |
.from_sql(db, query) ⇒ Object
Execute a query and create a data frame from the result
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# File 'lib/daru/io/io.rb', line 129 def from_sql(db, query) require 'daru/io/sql_data_source' SqlDataSource.make_dataframe(db, query) end |
.load(filename) ⇒ Object
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# File 'lib/daru/io/io.rb', line 194 def load filename if File.exist? filename o = false File.open(filename, 'r') { |fp| o = Marshal.load(fp) } o else false end end |
.save(klass, filename) ⇒ Object
Loading and writing Marshalled DataFrame/Vector
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# File 'lib/daru/io/io.rb', line 188 def save klass, filename fp = File.open(filename, 'w') Marshal.dump(klass, fp) fp.close end |